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(Nq' Model 2 Shets- S heet 1. C. A. HOUSTON. DRAFT REGULATOR AND SPARK ARRE$TER.

Patented Apr. 7, 1891.

WITNESSES:

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C. A. HOUSTON. DRAFT REGULATOR AND SPARK ARRESTER. No; 450,072. Patented Apr..7, 1891.

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UNITED STATES PATENT OFFICE...

CHARLES A. HOUSTON, OF SOMERVILLE, NEW JERSEY, ASSIGNOR OF ONE- THIRD TO VILLIAM B. MATI-IEIVSON, OF SAME PLACE.

DRAFT-REGULATOR AND SPARK-ARRESTER.

SPECIFICATION forming part of Letters Patent No. 450,072, dated April 7,1891.

Application filed July 8, 1890." Serial No. 858,118. (No model.)

To all whom it may concern:

Be it known that I, CHARLES A. HOUSTON, a citizen of the United States, residing in Somerville, in the county of Somerset and State of New Jersey, have invented certain new and useful Improvements in Draft-Generators and Spark-Arresters, of which the following is a specification.

This invention relates to tubular or multitubular steam-boilers, and particularly to that class of boilers wherein the tubes constitute the flues leading through the boiler from the furnace to the smoke-chamber.

The object of my invention is to provide improved means whereby a stronger and more uniform draft can be maintained, and to pro vide improved means for preventing the escape of sparks from the smoke-chamber.

To this end in carrying out myinvention I construct a tubular shell within the smokechan'iber to inclose the discharge end of the flues, and extending thence to and surrounding the jet of exhaust-steam or other gaseous jet utilized to induce the draft, and extending thence upwardly and surrounding the smokestack by a closed connection, such shell having a contracted aperture in its forward portion for the escape of sparks. I also provide a tubular screen surrounding the jet and connecting with the smoke-stack, and I provide improved means for ejecting the sparks from the shell.

In'the accompanying drawings, Figure 1 is a longitudinal vertical section of a locomotiveboiler and smoke-box and showing my invent-ion applied thereto. Fig. 2 is a vertical transverse section thereof cut on the line 2 2 in Fig. 1, and showing the shell in front elevation. Fig. 3 is a vertical transverse section of a locomotive smoke-box cut on the line 3 3 in Fig. 1, and looking from the rear. Fig. at is a vertical transverse section similar to Fig. 1, but-on a smaller scale, showing a simpler form of my invention; and Fig. 5 is a similar view of another form.

This invention relates more particularly to that class of draft-generators and spark-arresters which are shown and described in my application for patent filed October 9, 1889, Serial No. 326,420.

Referring to the drawings, let A represent the forward end of a locomotive-boiler; a a, the fines; B, the live-steam pipe; 0, the smokeboX, and D the exhaust-steam nozzle. These parts are constructed in the usual manner.

Leading from the'smoke-box O is the smokestack E, usually mounted directly over the nozzle D. According to my invention I extend the lowerportion of the smoke-stack into the smoke-box O. This is preferably done by inserting the tube E into'the lower end of the smoke-stack to form a downward continuation thereof. In the construction shown in Fig. 1 this tube continues downwardly and surrounds the nozzle D, being constructed at its lower part in the form of a screen E which is preferably tapered off at its lower end in the form of a cone and closely surrounds the upper portion of the nozzle D, on which it is seated.

Vithin the smoke-box C, I place a tubular shell F, arranged to inclose the discharge end of the flues a a, and extending thence forward and surrounding the jet end of the nozzle D, and extending thence upwardly and surrounding the lower portion of the stack by a closed connection therewith. Fis preferably constructed as a tube with an enlarged end for inclosing the iiues,.and extending forwardly and upwardly in a sweeping curve of rapidly-decreasing diameter toward its forward and upper end, where it incloses the lower end of the smoke-stack. The shell terminates ina raised forward portion 12 in front of the smoke-stack and near the top of the smoke-box O. The shell F is preferably The shell l constructed of sheet metal, the form shown in the drawings being made up of four piecesthe rear or flue pieces a c and the front halves d and e. These pieces are preferably secured together by bolts passing through their flanges, as best seen in Fig. 2. The halves d and 6, when removed from the piece 0, permit access to the interior of the shell. The pieces cl and e are constructed at their upper sides with opposite recesses, which, when the pieces are in position, closely surround the lower part of the smoke-stack, this being, in Figs. 1, 2, and 3, the upper por tion of the tube E. This connection between the shell F and the lube E is constructed, as shown in Figs. 1 and 3, as a closed connection, and the upper portion of the shell is continued upwardly as it surrounds the tube, so that the connection extends at an upward inclination from the back of the tube E to the front thereof.

For permitting the escape from the shell F of any sparks coming through the flues a a one or more apertures are provided in the shell. When one is used, it is preferably constructed in the upper portion 1) of the shell, and consists, preferably, of a contracted hole fin the forward side thereof, having outwardly-curved lips for facilitating the exit of sparks and retarding any back-draft through the hole. If desired, the holef may be omitted and an escape-aperture provided at some other point such, for example, as the hole 9 at the lower forward side of the shell, orboth of these holes may be used at the same time. The holesfaud g are located atpoints where any sparks entering the shell Fwill tend to pass. As the draft through the shell goes upwardly through the screen E and out through the smoke-stack E under the suction of the jet from the nozzle D, the sparks carried through the tines will be carried through the shell F in a sweeping curve with the draft. Consequently centrifugal force will cause them to seek the outer and forward side of the shell up which they will travel. The heavier sparks will fall against thelower portion of the shell and pass out through the hole g, while those which rise above that hole will be carried up and pass out of the holef. I-Ieavy sparks which strike the screen E and then fall back are preferably ejected through the hole g by means of an auxiliary jet directed toward the latter. This preferably consists of two pipes h 72, having their ends extending into the respective compartments of the exhaust-steam nozzle D, and ex tending thence upwardly and laterally and terminating in jet-nozzles at the respective sides of the exhaust-steam nozzle D, the pipes being shaped to catch a portion of the current of exhaust-steam passing through the nozzle D and dischargingthe portion of steam so caught through their outer ends upwardly along the lower front wall of the shell F and toward the hole 9. The jet of steam so discharged will carry out any sparks in its path.

Preferably an internal apron G is provided within the shell F for isolating the hole g from thejet end of the exhaust-nozzle D, as best seen in Figs. 1 and 3. This apron preferably consists of a sheet-metal partition bolted to the section 6 of the shell F at 1', and extending thence downwardly from the upper side of the hole g and continuing in adirection parallel with the lower front wall of the shell F and terminating over the ends of the jet-pipes h h. The apron G closely surrounds the exhaust-steam nozzle D below the tubular screen E and serves as a partition which prevents the suction from the exhaust-steam jet from d rawing'an inward current through the hole g, while it also serves to'guide the auxiliary jet of steam outwardly through said hole.

The exhaust-pipe from the air-pu mp of the engine is shown atj entering the smoke-box C and carried through the latter to a core in the nozzle D, which core terminates near the upper end of the nozzle in a small jet at the forward side thereof. WVhen the steampump is used, the exhaust therefrom passing fromthe pipej and the core k jets out of the upper end of the latter within the screen E and toward the smoke-stack, thereby supplementing the draft. creating a draft when the engine is not in operation is carried through the p ipel, enterin g the smoke-box O and c'lischarging into the core m in the nozzle D discharging through the upper end of this coreinto the screen E as best seen in Fig. l. I v

In operation the exhaust-steam jet from the nozzle D, through the screen E a'nd pipeE and out of the smoke-stack, causesa partial vacuum within the shell F, which creates a draft from the-fines a a, and the products of combustion are carried through the latter into the shell F, through the screenEfl'a'n d out of the smoke-stack with the exhauststeam. The draft is so closely confined within the shell F, by reason of the closed connection; between the latter and the smoke-stack and the contracted spark-aperture, that the draft is practically isolated from the interior-of the smoke-box and confined directly to theflu'es a a, thereby securingthe full force of the exhaust-suction independently of the condition inside the smoke-box. The sparks carried with the draft are guided onwardly inthe direction of their motion until they reach thespark-escape aperture, whereby their mo mentum is availed of to discharge them.

My invention provides an improved draftgenerator and spark-arrester for boiler-furnaces, which is more effective than thoseheretofore used, which dispenses with the was sity of many complicated and draft-retarding screens and similar devices placed in the smoke-box for preventing the escape of sparks therefrom. Itpermits the use of an exhauststeam nozzle of larger diameter than h eretm fore, and in practice it has been found to'effect a saving of twenty-five per cent'u min the fuel required in proportion tothe power used. By isolating the draft from the smoke-box it' is only necessary for an exhaust-steam jet to maintain the desired rarefaction within the shell F, as no material part of the force of the exhaust is expended in overcoming leaks in the smoke-box or defective joints there'inl This invention can be variously modified without departing from its essential features, the construction heretofore described being the preferred form.

In Fig.4 a simpler form embodying" myinvention is shown. In this construction the smoke-stack E extends into the shell Fand terminates therein over the end of the ex- The special steam-jet for haust-nozzle D. The latter is constructed as a simple nozzle discharging within the shell F. The shell F incloses the lower end of the smoke-stack by a closed connection, as well as the upper end of the nozzle D, and terminates at its upper part b in the contracted aperture f.

Fig. 5 shows another form of myinvent-ion wherein it is used with especial reference to increasingthe draft. In this construction the shell F is entirely closed, surrounding the nozzle D and the lower end of the stack E by closed connections, whereby the draft is entirely confined within the shell. In this construction no provision is made for discharging sparks from the shell F. The sparks which do not escape through the stack when this construction is used will be removed from time to time, as they accumulate in the shell F, in any convenient manner.

lVhat I claim is, in draft-generators and spark-arresters, the following-defined novel features and combinations, substantially as hereinbefore set forth, namely:

1. The combination, with a steam-boiler having flues through it, a smoke-chamber into which said fiues discharge, a smoke-stack leading from the latter, a gaseous jet for creating a forced draft through the fines, and a screen surrounding the jet and extending thence toward said smoke-stack, of a tubular shell within said chamber arranged to inclose the discharge end of the fines at one end, and

extending thence to and surrounding the jet below said screen, and extending thence upwardly and surrounding said stack above said screen, said shell constructed with a contracted aperture for the escape of sparks in its forward side, whereby the draft created by the jet is confined within said shell, and the sparks entering said shell can escape through said aperture.

2. The combination, with a steam-boiler having fines through it, a smoke-chamber into which said fiues discharge, a smoke-stack leading from said chamber, a jet-nozzle discharging into said stack, and a tubular screen surrounding said jet-nozzle and leading to said stack, of a tubular shell inclosing the ends of the fines at one end surrounding the jet-nozzle, and extending thence upwardly and surrounding the lower end of the smoke-stack by a closed connection therewith, and said shell constructed with a contracted aperture in its upper and forward side for the escape of sparks, and with a contracted aperture in its lower and forward side, whereby the draft created by said jet-nozzle is confined within said shell and the sparks in the lower part of the latter may escape through said lower aperture and those in the upper part thereof may escape through the upper aperture.

3. The combination, with a steam boiler having flues through it, a smoke-chamber into which said flues discharge, a smoke-stack leading from said chamber, a steam-nozzle discharginginto said smoke-stack, and a tubular screen surrounding said nozzle and extending thence toward said stack, of a tubular shell within said smoke-chamber inclosing the ends of the tines at one end and surrounding the jet-nozzle, and extending thence upwardly and closely surrounding the lower end of said stack, said shell constructed with a contracted aperture in its forward side communicating with said chamber for the escape of sparks, and a steam-jet discharging within said shell toward said aperture for expelling the sparks through it and into the smoke-chamber,whereby the draft created by the jet-nozzle is con fined within said shelland the sparks in the latter are expelled therefrom through said aperture by said steam-jet.

4;. The combination, with a boiler having flues through it, and a smoke chamber into which said fiues discharge, of a smoke-stack leading from said chamber, an exhaust-steam nozzle discharging into said stack and a screen surrounding said nozzle, of a tubular shell inclosing the endsof the flues at one end and surrounding said nozzle, and extending thence upwardly toward said stack, said shell construoted with a contracted aperture for the escape of sparks in its forward side and having an internal apron above said aperture, whereby sparks entering said shell may pass beneath said apron and escape through said aperture, and the draft created therein by said steam-nozzle is protected by said apron from said aperture.

5. The combination, with a boiler'having flues through it, and a smoke-chamber into which said fiues discharge, of a smoke-stack leading from said chamber, an exhaust-steam nozzle discharging into said stack, and a screen surrounding said nozzle, of a tubular. shell inclosing the ends of the flues at one end and surrounding said nozzle, and extending thence upwardly toward said stack, said shell constructed with a'contracted aperture for the escape of sparks in its forward side and having an internal apron, and an auxiliary steam-jet within said shell and discharging beneath said apron and toward said aperture, whereby sparks within said shell are discharged by said jet throughsaid aperture.

'6. The boiler A, having flues through it, smoke-box C, into which said flues discharge, smoke-stack E, tubular extension E thereof, exhaust-nozzle D and screen E and the shell F, inclosing the ends of the flues at one end and extending thence forward and surrounding the nozzle D and screen E and surrounding the tubular extension E" bya closed connection therewith, said shell constructed with contracted apertures f and g, and having internal apron G, in combination with the aux iliary jet-pipe h, constructed to take steam from the exhaust-nozzle D and discharge it in a jet beneath the apron G, all as and for the purpose set forth.

7. The combination, with a steam-boiler having flues through it, a smoke-chamber into which said flues discharge, a smoke-stack lead- IOC ing from said chamber, and a jetnozzle discharging into said stack, of a tubular shell within said chamber inclosing the ends of the fines at one end, surrounding the jet-nozzle by a closed connection, and extending thence upwardly and surrounding the lower end of the smoke-stack by a closed connection therewith, whereby the draft created by said jetnozzle is confined Within said shell. I

8. The combination, with a steam-boiler having flues through it, a smoke-chamber into which saidflues discharge, a Smokestack leading from said chamber, and a jet-nozzledischarging into said stack, of a tubular shell Within said smoke-chamber inclosing the ends of the fines at one end, surrounding the jet-nozzle and extending thence upwardly and surrounding the lower end of the smoke-stack by a closed connection therewith, and said shell constructed with a contracted aperture in its forward side for the escape 01: sparks, whereby the draft created by said jet-nozzle is confined Within said shell and the sparks in the latter may escape through said aperture.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

CHARLES A. HOUSTON.

Witnesses; GEORGE H. FRASER, CHARLES K. FRASER. 

